A wind dependent desert aerosol model: radiative properties /

This report presents a desert aerosol model that predicts aerosol radiative properties during background and severe dust storm conditions. The model treats the desert aerosol as an external mixture of natural carbon, water soluble and sand particles. The sand consists of two kinds of particles, pure quartz and quartz contaminated with a small amount of hematite. Mie calculations are performed using different size distributions and indices of refraction for each type of particle, and then a volume-weighting scheme is used to obtain the radiative properties of the aerosol as a whole. Attenuation coefficients, single scattering albedo and asymmetry parameter are given for 68 wavelengths between 0.2 and 300 micro. The results indicate that extinction is wavelength dependent for background conditions, but increases and becomes nearly constant for dust storm conditions. Indices of refraction, Desert aerosol, Aerosol modeling, Single scattering albedo, Radiative transfer, Optical properties.Research supported by the Air Force Geophysics Laboratory, United States Air Force, Hanscom AFB, Massachusetts.Performing organization : OptiMetrics, Inc., Burlington, Massachusetts."19 April 1988."Includes bibliographical references (pages 70-74).Appendix A. Aerosol fractions by volume as a function of wind speed -- Appendix B. Mie scattering calculations for the three components -- Appendix C. Radiative properties of the Desert Aerosol Model as a function of wind speed.This report presents a desert aerosol model that predicts aerosol radiative properties during background and severe dust storm conditions. The model treats the desert aerosol as an external mixture of natural carbon, water soluble and sand particles. The sand consists of two kinds of particles, pure quartz and quartz contaminated with a small amount of hematite. Mie calculations are performed using different size distributions and indices of refraction for each type of particle, and then a volume-weighting scheme is used to obtain the radiative properties of the aerosol as a whole. Attenuation coefficients, single scattering albedo and asymmetry parameter are given for 68 wavelengths between 0.2 and 300 micro. The results indicate that extinction is wavelength dependent for background conditions, but increases and becomes nearly constant for dust storm conditions. Indices of refraction, Desert aerosol, Aerosol modeling, Single scattering albedo, Radiative transfer, Optical properties.Mode of access: Internet